1. Field of the Invention
The present invention relates generally to the field of archery and more specifically, to an insert capable of being utilized within either end of an arrow shaft to allow engagement of a nock or a point to the arrow shaft.
2. Background Art
Archery has served to provide sustenance and recreation since prehistoric times. Wooden arrows have been replaced with aluminum, fiberglass and carbon fiber arrows. While these new materials impart beneficial characteristics to modern arrows, some problems are also introduced.
For example, to properly cut a hollow aluminum arrow shaft to a length unique to each individual archer, special tools are required so as not to deform the shaft or create burrs at the cut end thereof. Due to the ever heightening standards of accuracy in archery, even a small burr left at the end of a cut arrow shaft may sufficiently affect proper positioning of a nock insert or a point insert enough that an unacceptable flight path could result.
Modern arrow shaft materials and the desire of most archers to change points from a practice point a broadhead point without great effort necessitate not only special cutting tools, but also special methods for attaching arrow points and nocks to the shaft.
When an individual wishes to attach a point to a modern arrow shaft, a point insert is typically glued into the point end of a hollow arrow shaft to provide a secure mounting base for a variety of points which then can be threaded into the insert. To glue the point insert into the arrow shaft the insert is typically heated along with a heat sensitive adhesive stick which is then applied to the insert before press fitting the insert into a heated hollow arrow shaft. Formed within the insert is a threaded aperture capable of receiving a variety of points. Some points are still glued directly into the arrow shaft but direct adhesion does not allow quick point changes in the field.
At the other end of the arrow shaft a nock must be assembled to the shaft. The majority of arrows now in use utilize a glue-in insert from which projects a swage. A nock having a hollow end corresponding in size and shape to the swage is then glued over the swage and permanently bonded. The disadvantage of this system, however, is that the nock may be rotated or "indexed" after it is glued onto the swage. To overcome this problem, inserts have been developed which are glued into the arrow shaft and then receive a nock having a shank in press fit engagement. Using this system, a nock insert and nock capable of receiving a bowstring are then attached to the arrow shaft in the same manner as the point end except the nocks are press fit into the nock insert to allow adjustment of the nock after insertion into the nock insert. Nocks must be rotated within the nock insert or "indexed" in order to obtain optimum flight characteristics when the arrow is released from the bow. During passage of the arrow over an arrow rest, portions of the fletching of the arrow come in contact with the arrow rest. By indexing the nock, the contact between the fetching and the arrow rest of the bow may be varied to reduce the effect of the contact on the flight path of the arrow.
Although these methods for attaching nocks and points to arrow shafts allow rapid changing of points and indexing of nocks, these attachment systems introduce their own problems. For example, when the point insert is inserted into the arrow shaft, even slight variations in the longitudinal axis of the point insert in relation to the longitudinal axis of the arrow shaft can result in an inaccurate flight path.
Because of the substantial impact which the point of a modern arrow undergoes due to higher flight speeds, vibration from the impact travels through the point into the metallic point insert and causes points to work loose. As the point vibrates loose, the point may alter the flight path of the arrow.
As nock inserts capable of receiving press nocks do not have any internal surfaces which can be gripped to remove the nock insert, archers wishing to salvage nock inserts from damaged arrows must attempt to remove the nock insert from a heated arrow with pliers. Unfortunately, the pressure required to remove the nock insert often results in deformation of the nock insert due to the pressure which must be applied by the pliers.
Because a different point insert and nock insert are required, both inserts must be purchased in a store.
In addition to adjusting the length of an arrow, other considerations such as balance and which form of fetching will be utilized must also be examined. For example, if the fetching on an arrow is changed from feathers to plastic vanes, the balance of the arrow will be altered by the heavier plastic vanes. The weight of the point insert and the nock insert will also affect the balance of the arrow. Although some bias toward the front of the arrow is desirable, too much bias in that direction may result in an arrow which has an erratic flight path. As the length of an arrow shaft depends upon the draw of the bow and the size of the archer, the length of the arrow should not be altered merely to correct an improperly balanced arrow. To alter the balance of an arrow without changing the length of the arrow some archers have placed weights near the nock insert to properly balance the arrow. The addition of weights to an arrow, however, obviates the benefits derived from the lightweight modern materials.
In addition, the adhesives used with current systems often scrape some of the adhesive off when inserts are pressed into the arrow shafts resulting in uneven application of the adhesive and premature failure of the joint. The current adhesive systems are also cumbersome as the user must heat a heat-sensitive adhesive stick and then paint the adhesive onto the insert prior to pressing the insert into the arrow shaft.